mp_0040: Usage of return value of a function
Since R2024b
Guideline Publication
Control Algorithm Modeling Guidelines - Using MATLAB®, Simulink®, and Stateflow®
Sub ID Recommendations
- NA-MAAB — a 
- JMAAB — a 
MATLAB Versions
All
Rule
Sub ID a
The return values of functions shall be assigned to variables before use.
ret1 = func1(arg1); ret2 = func2(arg2); ret = ret1 + ret2;
ret = func1(arg1) + func2(arg2);
Rationale
Sub ID a:
- Although it is not syntactically incorrect to use the return values of functions directly, the results may vary depending on the order of the function evaluation. - Readability improves where the return values of functions are assigned to variables before use, rather than where the return values are used directly in operations. 
Verification
Model Advisor check: Check for utilization of the return value of functions (Simulink Check)
Last Changed
R2024b
Version History
Introduced in R2024b